Buffer 'card->dai_link' is reallocated in 'meson_card_reallocate_links()',
so move 'pad' pointer initialization after this function when memory is
already reallocated.
Kasan bug report:
==================================================================
BUG: KASAN: slab-use-after-free in axg_card_add_link+0x76c/0x9bc
Read of size 8 at addr ffff000000e8b260 by task modprobe/356
CPU: 0 PID: 356 Comm: modprobe Tainted: G O 6.9.12-sdkernel #1
Call trace:
dump_backtrace+0x94/0xec
show_stack+0x18/0x24
dump_stack_lvl+0x78/0x90
print_report+0xfc/0x5c0
kasan_report+0xb8/0xfc
__asan_load8+0x9c/0xb8
axg_card_add_link+0x76c/0x9bc [snd_soc_meson_axg_sound_card]
meson_card_probe+0x344/0x3b8 [snd_soc_meson_card_utils]
platform_probe+0x8c/0xf4
really_probe+0x110/0x39c
__driver_probe_device+0xb8/0x18c
driver_probe_device+0x108/0x1d8
__driver_attach+0xd0/0x25c
bus_for_each_dev+0xe0/0x154
driver_attach+0x34/0x44
bus_add_driver+0x134/0x294
driver_register+0xa8/0x1e8
__platform_driver_register+0x44/0x54
axg_card_pdrv_init+0x20/0x1000 [snd_soc_meson_axg_sound_card]
do_one_initcall+0xdc/0x25c
do_init_module+0x10c/0x334
load_module+0x24c4/0x26cc
init_module_from_file+0xd4/0x128
__arm64_sys_finit_module+0x1f4/0x41c
invoke_syscall+0x60/0x188
el0_svc_common.constprop.0+0x78/0x13c
do_el0_svc+0x30/0x40
el0_svc+0x38/0x78
el0t_64_sync_handler+0x100/0x12c
el0t_64_sync+0x190/0x194
Fixes: 7864a79f37b5 ("ASoC: meson: add axg sound card support")
Cc: Stable@xxxxxxxxxxxxxxx
Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
Reviewed-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Link: https://patch.msgid.link/20240911142425.598631-1-avkrasnov@xxxxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
diff --git a/sound/soc/meson/axg-card.c b/sound/soc/meson/axg-card.c
index 8c5605c1e34e..eb0302f20740 100644
--- a/sound/soc/meson/axg-card.c
+++ b/sound/soc/meson/axg-card.c
@@ -104,7 +104,7 @@ static int axg_card_add_tdm_loopback(struct snd_soc_card *card,
int *index)
{
struct meson_card *priv = snd_soc_card_get_drvdata(card);
- struct snd_soc_dai_link *pad = &card->dai_link[*index];
+ struct snd_soc_dai_link *pad;
struct snd_soc_dai_link *lb;
struct snd_soc_dai_link_component *dlc;
int ret;
@@ -114,6 +114,7 @@ static int axg_card_add_tdm_loopback(struct snd_soc_card *card,
if (ret)
return ret;
+ pad = &card->dai_link[*index];
lb = &card->dai_link[*index + 1];
lb->name = devm_kasprintf(card->dev, GFP_KERNEL, "%s-lb", pad->name);
